A biological measurement and stimulation system comprises an interrogator device, located in, on, or near a patient's head, in communication with many medical implants comprising small wireless probes implanted in the patient's brain. These medical implants can take measurements of and/or stimulate portions of the patient's brain, based on communications received from the interrogator device, which can act as a controller for the medical implants. Further, the medical implants may be powered by the interrogator device (e.g., via a coiled antenna drawing power from communications and/or other signals or fields generated by the interrogator device).
However, where a system has many medical implants (e.g., thousands or more), it may take a long time for the interrogator device to communicate with each of them. Furthermore, architectures in which the interrogator device has only a single antenna may produce an uneven field for powering the medical implants, which can result in medical implants getting too much or too little power. Furthermore, in systems having many medical implants, the length of time needed for the interrogator device to communicate with the medical implants may require the antenna to create a field for a length of time that exceeds relevant exposure limits, which limit the duration the brain can be exposed to such fields.